The present invention relates to a differential mixer and a method which, for example, can reduce a leak component of a local oscillation differential signal.
In a wireless receiving apparatus, a primary mixer mixes a high frequency signal and a local oscillation differential signal that are inputted and outputs an intermediate frequency differential signal. In the primary mixer, a leak component of a local oscillation signal (local signal) causes saturation of a post-stage circuit and undesired frequency mixing, so that the leak component is a problem causing deterioration of characteristics of the receiving apparatus.
A BLE (Bluetooth (registered trademark) Low Energy) transceiver having a low noise amplifier and a primary mixer is described in Yao-Hong Liu, et al., “A 1.9 nJ/b 2.4 GHz multistandard (Bluetooth Low Energy/Zigbee/IEEE802.15.6) transceiver for personal/body-area networks”, 2013 ISSCC, Pages: 446-447 (Non Patent Literature 1). Non Patent Literature 1 describes that the primary mixer is a complementary push-pull mixer which performs single end-differential conversion (differential conversion) at the same time as frequency conversion. However, Non Patent Literature 1 does not describe that the leak component of the local oscillation signal is reduced.